Pranks are fun, but finding a way to maximize the affect of a prank can be tricky. Toilet papering the whole campus or repainting all of the parking spaces slightly smaller can take a long time and a lot of resources. A better plan of attack is to booby trap the choke points where your victims are forced to pass through. Think like a guerrilla. A dorm doorway is a good idea.

Now, what can we do to the people going in and out? Startling them with loud noises and lights may cause some panic, but spraying them with a perfume will be pleasantly annoying to all who wander by.

Today, we make a perfume attack cannon using Arduino, sonar, and a Swiffer WetJet mop.

Materials

Step 1 Mod the Mop

You can activate the pump on a Swiffer WetJet by taking apart the handle and replacing the switch with a transistor or relay, but for the sake of keeping a working mop, a servo-activated system will work just as well. Affix your servo so that it presses down the Swiffer button when activated.

WetJet bottles are not refillable, but plastic is pretty easy to get through. Poke a hole in the top of a used WetJet bottle and pour in your fragrance of choice! Be kind and try not to spray skunk stench on all the people who know where you live. A flowery perfume can have just as much affect.

Step 2 Enclosure

We will want to make an enclosure for the Arduino, battery, and sonar sensor. A cardboard box is a good incognito project holder. Cut two holes in the side of the box for the ping sonar sensor to protrude from.

You can even lean your mop against the box to minimize the length of the servo wire and position the pump jet so it sprays towards the doorway.

Step 3 Circuit

This circuit is so simple that we don't even need a breadboard. Wire your sonar sensor and servo as shown below. Note that the infrared distance sensor represents the sonar sensor in the image.

Step 4 Code

The code for this project is identical to the wildlife camera project. Download the wildlife camera code here and set the activation distance to whatever you like.

Step 5 Cover Your Tracks

You will want to get a trusted friend of yours to collect the Swiffer ambush device while nobody is looking. It is best to keep your identity hidden when pulling mass pranks. You never know who you might have sprayed with flowery perfume on their way out to a job interview.

With great power comes great responsibility. Be kind and don't spray horrible things at strangers.

The Swiffer is really a great pump to use with any microcontroller. You could use it to mist your garden, add chemicals to your pool, or for dispensing drinks. What would you use a Swiffer pump for? Let us know in the comments below! If you have a question, feel free to message me personally or post in the forum.

Don't Forget About Our Mad Science Contest!

Don't forget! We are currently accepting entries into our photo contest for a chance to win your very own lucid dreaming goggles kit! Just post a picture on the corkboard of a project you have made or are currently working on. All projects are welcome. Here is my example entry.